@Article{LangeLutzJSL05,
  author =       "M. Lange and C. Lutz",
  title =        "2-ExpTime lower bounds for Propositional Dynamic Logics with intersection",
  journal =      "Journal of Symbolic Logic",
  volume = {70},
  number = {5},
  pages = {1072--1086},
  year =   {2005},
}